If you have decided to add online advertising to your site, the next step is to decide which ad sizes in particular you want to add. This is a long term decision as it is impractical to redesign you site every time you change your mind about including an ad unit.
Our ad size guide explains the most common ad units of the moment to website owners, with information about the ad unit itself as well as some advice directly for website owners. Unfortunately we can’t tell you exactly what would be best for you as sites differ so wildly. We can however tell you which ad units generally perform the best, earn the most, as well as some other useful hints and tips.
Which ad sizes you put on your site depends more on the number of visitors you receive than the design of your site. Although it can be tempting to fill every spare space with an ad, this strategy will most likely not make you the most money. This is because most ad units are under-used and therefore the quality of the ad you receive on irregular sized ad units may compromise the quality of your site.
For most sites the balance to strike between profit and annoyance to users is to just include the main three IAB Standard Ad Units – 160×600, 300×250 (or 300×600) and 728×90, such as we have done here on The Online Advertising Guide. However sites with a lot of traffic will have different priorities and budgets than sites with low traffic, so they may want to consider things differently.
Whether you are a large or small site, please check the relevant link: